In the prior art, it is already known for motor vehicles to be equipped with sensor devices suitable for sensing the environment. In particular, mono or stereo camera devices, radar devices and ultrasound devices are already present in a multiplicity of new vehicles as standard basic equipment or are at least available as special equipment. Furthermore, wirelessly transmitting vehicle-to-X communication devices are known in the prior art which enable an information exchange with surrounding vehicles and surrounding infrastructure. Although vehicle-to-X communication devices of this type are currently still not in widespread use in motor vehicles, a rapid market penetration is expected over the next few years, which, in particular, will also be promoted by legal provisions and regulations.
In this connection, a central control device for a plurality of assistance systems provided in a motor vehicle is known from DE 10 2007 058 192 A1 which is at least partially equipped with environment sensors, wherein, according to DE 10 2007 058 192 A1, a telematics system is also understood to be an environment sensor. The central control device is connected at data level to the individual assistance systems and verifies the plausibility of the information of individual environment sensors by means of the information of different environment sensors. For example, the image information of a camera may confirm the distance measurement of a radar sensor. Individual sensor information can thus be confirmed and is present in redundant form. Such a coupling of individual signals of different sensors is also known as sensor fusion.
DE 10 2011 077 998 A1 discloses a method for information validation of a vehicle-to-X message by means of environment sensors. A vehicle-to-X communication device and the environment sensors of a motor vehicle interwork here in such a way that the information content of vehicle-to-X information is reliably validated by means of the environment sensors even if the available environment sensors capture the information content described by the vehicle-to-X information only briefly or with constant interruptions. Vehicle-to-X information can thus be validated or rejected as insufficiently trustworthy even in situations with only restricted environment-sensing possibilities.
A method and a system for validating a vehicle-to-X message are known from DE 10 2011 079 052 A1. Here, a wirelessly transmitted vehicle-to-X message is received by an antenna arrangement having at least two antenna elements, wherein the electromagnetic field strength of the vehicle-to-X message is sensed by the antenna elements with different power densities due to different, direction-dependent receive characteristics of the antenna elements. From the ratio of the different power densities in the antenna elements, the receiver determines a position of the transmitter relative to the receiver. The vehicle-to-X message furthermore contains an absolute position of the transmitter based on GPS data, from which the receiver of the vehicle-to-X message calculates a further position of the transmitter relative to the receiver via its own absolute position. By means of a comparison of the two relative positions, the received vehicle-to-X message can then be validated if the two positions match one another, or rejected if the positions differ from one another.
However, the methods and devices known from the prior art have the disadvantage that the largest possible number of different sensors of different sensor types are required for the reliable sensing of objects and, in particular, for validating a detected object, which in turn incurs high equipment costs for motor vehicles of this type.
The object of the invention is therefore to propose a method which allows the environment sensor equipment cost incurred according to the prior art to be reduced without entailing information losses.
This object is achieved according to the invention by the method for position determination of objects by means of communication signals as described herein.